1. Orcas are in danger because there is pollution in the sea. 2. They're hunting because they're hungry. 3. I don't swim because I don't like being in water. 4. She's having a good time because she's at the aquarium. 5. He's running because he's late. 6. They're hiding because they're scared.
1 - c / 2 - e / 3 - a / 4 - f / 5 - b / 6 - d